NASA has posted a contract opportunity notice, also known as a request for information, from commercial space orgs who can service the Hubble Space Telescope.
Hubble was always looked after by NASA astronauts flying on the Space Shuttle, yet the last Hubble Space Telescope (HST) servicing mission was the STS-125 Space Shuttle flight, launched on May 11, 2009. At the time, scientists hoped the mission would add another five years of operational life to the venerable spacecraft. Almost 17 years on, the HST (aka Hubble) is still delivering science.
However, time is running out for the observatory. NASA reckons there is a 10 percent chance it could reenter the Earth's atmosphere by September 2032, rising to 50 percent by December 2033. As the end of the Swift mission showed, increased solar activity can cause greater-than-anticipated atmospheric drag.
Also, like Swift, Hubble has no propulsion system, and so when it reenters (as it will, without intervention), the reentry will be uncontrolled. Hubble is sufficiently massive that there is a remote chance somebody on the ground could have a very bad day when that happens.
As such, one mission option suggested by NASA is a vehicle to grapple the observatory and perform a controlled reentry and disposal.
However, there are other options. Something to boost the telescope's orbit up to at least 600 km, or another to "enhance its ongoing performance and increase its resilience and expected on-orbit lifetime."
Both are intriguing options, and important since, as NASA acknowledges, no replacement for Hubble is expected before the 2040s, when the Habitable Worlds Observatory (HWO) could become operational. Despite the James Webb Space Telescope (JWST) and the Nancy Roman Space Telescope, Hubble remains in high demand, with NASA reporting a 7:1 oversubscription.
Before becoming NASA Administrator, Jared Isaacman advocated a SpaceX mission to boost the Hubble, but the idea was ultimately rejected. Similar plans could now be dusted off. NASA's requirement is for a mission to occur by 2032, and not harm the Hubble.
A soft-capture mechanism was fitted to Hubble during the STS-125 mission, which will mean docking with the spacecraft will be easier than the grappling planned for Swift. Then, the question is what to do with it. A controlled reentry is one option. The other options – boosting to a higher altitude or "enhance its ongoing performance and increase its resilience" are intriguing. Northrop Grumman's Mission Extension Vehicle (MEV), for example, is capable of on-orbit servicing and extending the lifetime of satellites. The Hubble is an order of magnitude more challenging, but the technological hurdles can be overcome with time and funding.
Last year, spoke with Dr John Grunsfeld, one of the astronauts (now retired) who worked on Hubble during the STS-125 mission. Grunsfeld told us that the veteran spacecraft faced death by a thousand cuts as its budget was whittled away. The observatory itself recently switched from three to one gyro mode (the telescope uses gyros to control where it is pointed) to eke out a few more years of operational life.
At this point, NASA is looking for information and comment – this isn't a request for proposals. There is no indication of how much the agency expects to pay. However, the timescale is immutable. Without intervention, Hubble will make an uncontrolled reentry in the coming years. ®