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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
80
GRADE
B
FIX
1
REVIEW
4
PASS
4
INFO
0
Probed from New York, United Stated
301 Moved Permanently
Checks
9
4 PASS 4 REVIEW 1 FIX
D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

C
Crawlability
Action
robots.txt present, sitemap with 0 URLs
REVIEW
robots.txt present, sitemap with 0 URLs
Info::
robots.txt is present
Got: 10240 bytes
Info::
sitemap.xml is present
Warning::
sitemap.xml contains invalid XML
Search engines may not be able to parse the sitemap. Fix XML validation errors.
Warning::
sitemap.xml is empty — no URLs found
An empty sitemap provides no value. Add <url> entries for your pages.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Search engines may not be able to parse the sitemap. Fix XML validation errors.

Why this matters

An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.

Learn more ▾

Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.

Source: sitemaps.org / Google Search Central

An empty sitemap provides no value. Add <url> entries for your pages.

Why this matters

An empty sitemap signals 'no content to index' to Google — actively harmful versus having no sitemap at all.

Learn more ▾

Google compares URLs in the sitemap against URLs it has crawled. An empty sitemap on a site with thousands of pages signals abandonment. Either populate it correctly (most CMSes auto-generate) or delete the file and let Google crawl normally.

Source: Google Search Central / sitemaps.org

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 10240 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
<!doctype html>
<html lang="en-US" prefix="og: https://ogp.me/ns#">
<head>
	<meta charset="UTF-8">
<script>
var gform;gform||(document.addEventListener("gform_main_scripts_loaded",function(){gform.scriptsLoaded=!0}),document.addEventListener("gform/theme/scripts_loaded",function(){gform.themeScriptsLoaded=!0}),window.addEventListener("DOMContentLoaded",function(){gform.domLoaded=!0}),gform={domLoaded:!1,scriptsLoaded:!1,themeScriptsLoaded:!1,isFormEditor:()=>"function"==typeof InitializeEditor,callIfLoaded:function(o){return!(!gform.domLoaded||!gform.scriptsLoaded||!gform.themeScriptsLoaded&&!gform.isFormEditor()||(gform.isFormEditor()&&console.warn("The use of gform.initializeOnLoaded() is deprecated in the form editor context and will be removed in Gravity Forms 3.1."),o(),0))},initializeOnLoaded:function(o){gform.callIfLoaded(o)||(document.addEventListener("gform_main_scripts_loaded",()=>{gform.scriptsLoaded=!0,gform.callIfLoaded(o)}),document.addEventListener("gform/theme/scripts_loaded",()=>{gform.themeScriptsLoaded=!0,gform.callIfLoaded(o)}),window.addEventListener("DOMContentLoaded",()=>{gform.domLoaded=!0,gform.callIfLoaded(o)}))},hooks:{action:{},filter:{}},addAction:function(o,r,e,t){gform.addHook("action",o,r,e,t)},addFilter:function(o,r,e,t){gform.addHook("filter",o,r,e,t)},doAction:function(o){gform.doHook("action",o,arguments)},applyFilters:function(o){return gform.doHook("filter",o,arguments)},removeAction:function(o,r){gform.removeHook("action",o,r)},removeFilter:function(o,r,e){gform.removeHook("filter",o,r,e)},addHook:function(o,r,e,t,n){null==gform.hooks[o][r]&&(gform.hooks[o][r]=[]);var d=gform.hooks[o][r];null==n&&(n=r+"_"+d.length),gform.hooks[o][r].push({tag:n,callable:e,priority:t=null==t?10:t})},doHook:function(r,o,e){var t;if(e=Array.prototype.slice.call(e,1),null!=gform.hooks[r][o]&&((o=gform.hooks[r][o]).sort(function(o,r){return o.priority-r.priority}),o.forEach(function(o){"function"!=typeof(t=o.callable)&&(t=window[t]),"action"==r?t.apply(null,e):e[0]=t.apply(null,e)})),"filter"==r)return e[0]},removeHook:function(o,r,t,n){var e;null!=gform.hooks[o][r]&&(e=(e=gform.hooks[o][r]).filter(function(o,r,e){return!!(null!=n&&n!=o.tag||null!=t&&t!=o.priority)}),gform.hooks[o][r]=e)}});
</script>

	<meta name="viewport" content="width=device-width, initial-scale=1">
	<link rel="profile" href="https://gmpg.org/xfn/11">

		<style>img:is([sizes="auto" i], [sizes^="auto," i]) { contain-intrinsic-size: 3000px 1500px }</style>
	
<!-- Search Engine Optimization by Rank Math PRO - https://rankmath.com/ -->
<title>Hubble Space Telescope - NASA Science</title>
<meta name="description" content="Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe."/>
<meta name="robots" content="follow, index, max-snippet:-1, max-video-preview:-1, max-image-preview:large"/>
<link rel="canonical" href="https://science.nasa.gov/mission/hubble/" />
<meta property="og:locale" content="en_US" />
<meta property="og:type" content="article" />
<meta property="og:title" content="Hubble Space Telescope - NASA Science" />
<meta property="og:description" content="Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe." />
<meta property="og:url" content="https://science.nasa.gov/mission/hubble/" />
<meta property="og:site_name" content="NASA Science" />
<meta property="article:publisher" content="https://www.facebook.com/NASA" />
<meta property="article:section" content="Hubble Space Telescope" />
<meta property="og:updated_time" content="2026-04-20T12:27:40-04:00" />
<meta property="og:image" content="https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-nov-2025-compressed.gif/jcr:content/renditions/cq5dam.web.1280.1280.gif" />
<meta property="og:image:secure_url" content="https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-nov-2025-compressed.gif/jcr:content/renditions/cq5dam.web.1280.1280.gif" />
<meta property="og:image:alt" content="Hubble" />
<meta property="article:published_time" content="2023-05-10T10:28:36-04:00" />
<meta property="article:modified_time" content="2026-04-20T12:27:40-04:00" />
<meta property="og:video" content="https://assets.science.nasa.gov/content/dam/science/missions/hubble/citizen-science/LocalGroupClusterTutorial.mp4" />
<meta property="og:video" content="https://www.youtube.com/embed/QFwfV2A1ZgY" />
<meta property="video:duration" content="300" />
<meta property="ya:ovs:upload_date" content="2023-05-10EDT10:28:36-04:00" />
<meta property="ya:ovs:allow_embed" content="false" />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:title" content="Hubble Space Telescope - NASA Science" />
<meta name="twitter:description" content="Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe." />
<meta name="twitter:site" content="@NASA" />
<meta name="twitter:creator" content="@NASA" />
<meta name="twitter:image" content="https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-nov-2025-compressed.gif/jcr:content/renditions/cq5dam.web.1280.1280.gif" />
<meta name="twitter:label1" content="Written by" />
<meta name="twitter:data1" content="Michelle Belleville" />
<meta name="twitter:label2" content="Time to read" />
<meta name="twitter:data2" content="Less than a minute" />
<script type="application/ld+json" class="rank-math-schema-pro">{"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://science.nasa.gov/#organization","name":"NASA","sameAs":["https://www.facebook.com/NASA","https://twitter.com/NASA"],"logo":{"@type":"ImageObject","@id":"https://science.nasa.gov/#logo","url":"https://assets.science.nasa.gov/dynamicimage/assets/science/psd/solar/bosf/images/editor-page-nasa-logo-250s.png","contentUrl":"https://assets.science.nasa.gov/dynamicimage/assets/science/psd/solar/bosf/images/editor-page-nasa-logo-250s.png","caption":"NASA Science","inLanguage":"en-US","width":"250","height":"250"}},{"@type":"WebSite","@id":"https://science.nasa.gov/#website","url":"https://science.nasa.gov","name":"NASA Science","alternateName":"National Aeronautics and Space Administration Science","publisher":{"@id":"https://science.nasa.gov/#organization"},"inLanguage":"en-US"},{"@type":"ImageObject","@id":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint","url":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint","width":"800","height":"450","caption":"Hubble Space Telescope Orbiting The Earth","inLanguage":"en-US"},{"@type":"WebPage","@id":"https://science.nasa.gov/mission/hubble/#webpage","url":"https://science.nasa.gov/mission/hubble/","name":"Hubble Space Telescope - NASA Science","datePublished":"2023-05-10T10:28:36-04:00","dateModified":"2026-04-20T12:27:40-04:00","isPartOf":{"@id":"https://science.nasa.gov/#website"},"primaryImageOfPage":{"@id":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint"},"inLanguage":"en-US"},{"@type":"Person","@id":"https://science.nasa.gov/author/mhbelleville/","name":"Michelle Belleville","url":"https://science.nasa.gov/author/mhbelleville/","image":{"@type":"ImageObject","@id":"https://science.nasa.gov/wp-content/uploads/2023/05/cropped-img-0085-jpg-1-96x96.webp","url":"https://science.nasa.gov/wp-content/uploads/2023/05/cropped-img-0085-jpg-1-96x96.webp","caption":"Michelle Belleville","inLanguage":"en-US"},"worksFor":{"@id":"https://science.nasa.gov/#organization"}},{"articleSection":"Hubble Space Telescope","headline":"Hubble Space Telescope","description":"Since its 1990 launch, NASA's Hubble Space Telescope has changed our fundamental understanding of the universe.","keywords":"Hubble Space Telescope, Hubble","@type":"Article","author":{"@id":"https://science.nasa.gov/author/mhbelleville/","name":"Michelle Belleville"},"datePublished":"2023-05-10T10:28:36-04:00","dateModified":"2026-04-20T12:27:40-04:00","image":{"@id":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint"},"name":"Hubble Space Telescope","@id":"https://science.nasa.gov/mission/hubble/#schema-5582442","isPartOf":{"@id":"https://science.nasa.gov/mission/hubble/#webpage"},"publisher":{"@id":"https://science.nasa.gov/#organization"},"inLanguage":"en-US","mainEntityOfPage":{"@id":"https://science.nasa.gov/mission/hubble/#webpage"}},{"@type":"VideoObject","name":"Hubble Space Telescope - NASA Science","description":"Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.","uploadDate":"2023-05-10T10:28:36-04:00","thumbnailUrl":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint","contentUrl":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/citizen-science/LocalGroupClusterTutorial.mp4","isFamilyFriendly":"True","@id":"https://science.nasa.gov/mission/hubble/#schema-13334230","isPartOf":{"@id":"https://science.nasa.gov/mission/hubble/#webpage"},"publisher":{"@id":"https://science.nasa.gov/#organization"},"inLanguage":"en-US"},{"@type":"VideoObject","name":"\u201cCosmic Sea Slug\u201d Appears in Hubble\u2019s 36th Birthday Image","description":"NASA is celebrating the 36th anniversary of the Hubble Space Telescope with a stunning new look at the Trifid Nebula, a star-forming region about 5,000 light...","uploadDate":"2026-04-20T07:07:16-07:00","thumbnailUrl":"https://assets.science.nasa.gov/content/dam/science/missions/hubble/videos/hubble-banner-animation-mar-2026.gif?w=800&amp;h=450&amp;fit=clip&amp;crop=faces%2Cfocalpoint","embedUrl":"https://www.youtube.com/embe
sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Critical::
HTTP version does not redirect to HTTPS
Got: HTTP 0 Expected: 301 redirect to HTTPS

www / non-www

301https://www.hubblesite.org/
200https://hubblesite.org/

Preferred variant: non-www

HTTP → HTTPS

http://hubblesite.org/

HTTP version does not redirect to HTTPS

B
TLS Certificate Expiry & Recommendations
171 days until leaf cert expires — 2 issues to address
REVIEW

Certificate validity

171
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
2 A records, 60 ms lookup
PASS
2 A records, 60 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 34.199.87.163, 44.193.165.237
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-408.awsdns-51.com, ns-745.awsdns-29.net, ns-1165.awsdns-17.org, ns-1763.awsdns-28.co.uk
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 60 ms
Got: 60 ms
A34.199.87.163, 44.193.165.237
AAAA—
CNAME—
NSns-408.awsdns-51.com, ns-745.awsdns-29.net, ns-1165.awsdns-17.org, ns-1763.awsdns-28.co.uk
MX—
TXT
google-site-verification=fN4wDfAZIdrKPMxKgekXHekmxgD_xDl1QDkmDCYAF9E
CAALookup not available with standard resolver
Resolved in 60 ms

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more ▾

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

A
Redirect Chain
1 redirect(s), 76 ms total
PASS
1 redirect(s), 76 ms total
Info::
Single redirect
Got: https://hubblesite.org → https://science.nasa.gov/mission/hubble/ (301)
Info::
Cross-domain redirect detected

https://hubblesite.org

67 ms · HTTP/1.1

301

https://science.nasa.gov/mission/hubble/

9 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://hubblesite.org30167 msHTTP/1.1
2https://science.nasa.gov/mission/hubble/2009 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

A+
Domain Intelligence
hubblesite.org — via Amazon Registrar, Inc., 25 years, 3 months old, hosted on AWS
PASS
hubblesite.org — via Amazon Registrar, Inc., 25 years, 3 months old, hosted on AWS
Info::
Domain registered until May 10, 2027 (1 years remaining)
Info::
DNSSEC is enabled
Info::
Registrar: Amazon Registrar, Inc.
Warning::
Registrar lock is NOT enabled
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Info::
Hosting: AWS
Got: AS14618
Domain expiry

329 days

May 10, 2027

SSL certificate

171 days

Issued by Amazon

Domain age

25 years, 3 months

Registered May 10, 2001

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS14618

54.146.102.45

Registrar

Amazon Registrar, Inc.

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar Amazon Registrar, Inc.
Created May 10, 2001 (25 years, 3 months ago)
Expires May 10, 2027 (1 years)
Last Updated April 10, 2026
Name Servers ns-1165.awsdns-17.org, ns-1763.awsdns-28.co.uk, ns-408.awsdns-51.com, ns-745.awsdns-29.net
DNSSEC Enabled
Hosting
IP Address 54.146.102.45
ASN AS14618 (AMAZON-AES - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.2s)

The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.

Why this matters

Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.

Learn more ▾

Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A+
HTTP Probe Timing
Total 67 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
22 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
7 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
8 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
67 ms
Total Time Total request time from DNS lookup through full response.
67 ms

Connection waterfall

DNS Lookup 22 ms TCP Connect 7 ms TLS Handshake 8 ms Server Processing 30 ms Content Transfer 0 ms
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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