NASA Makes Another Desperate Call to Save Hubble from Orbit Decay

TL;DR: Accelerated atmospheric drag from Solar Cycle 25 has pushed Hubble below 515 kilometers, prompting NASA to reopen commercial solicitations to boost the observatory or face an uncontrolled deorbit in the 2030s.

The Hubble Space Telescope has survived failed gyroscopes, distorted mirrors, and the retirement of the space shuttle fleet that maintained it for two decades. Yet orbital mechanics and solar weather are proving harder to outmaneuver than budget cuts.

NASA’s Goddard Space Flight Center has quietly issued an updated Request for Information (RFI) to the commercial space sector, inviting aerospace operators to submit viable proposals to reboost the 36-year-old observatory to a higher, safer orbit. The agency is also asking for proposals on how to safely guide the 12-ton telescope through a controlled atmospheric reentry if an orbital lift proves too risky.

The renewed urgency stems from solar physics. Peak solar activity throughout 2024 and 2025 expanded Earth’s thermosphere far more aggressively than conservative models projected, increasing atmospheric drag against Hubble’s bulky bus. The telescope, which orbited comfortably near 615 kilometers when deployed in 1990, has drifted below 515 kilometers. At its current decay rate, atmospheric drag could drag Hubble into an unguided dive across populated latitudes by the mid-2030s.

Hubble Space Telescope berthed in space shuttle cargo bay — Photo by meomupmofilm on Pexels

The Physics of Hubble’s Descent

Hubble was never equipped with onboard propulsion. Every past altitude adjustment came courtesy of the Space Shuttle’s reaction control thrusters while the telescope was clamped safely inside the orbiter’s payload bay. When STS-125—the final shuttle servicing mission—pulled away in May 2009, astronauts left behind the Soft Capture Mechanism (SCM), a low-profile ring interface designed to let a future uncrewed spacecraft latch onto Hubble’s aft bulkhead.

Until recently, that ring was viewed primarily as a docking target for a disposal tug to crash the observatory into the South Pacific. But Hubble’s primary optical instruments remain scientifically productive, even after NASA trimmed operations down to a one-gyroscope stabilization mode to stretch hardware longevity.

Milestone / Parameter	Value	Details
Launch Altitude (1990)	~615 km	Deployed via Space Shuttle Discovery (STS-31)
Post-STS-125 Altitude (2009)	~565 km	Final shuttle servicing mission boost
Current Altitude (Late 2026)	~512 km	Accelerated decay from peak solar thermospheric heating
Critical Altitude Floor	~500 km	Point at which drag begins runaway orbital degradation
Telescope Mass	11,110 kg	Too dense to fully disintegrate upon atmospheric reentry

Engineers at NASA Goddard Space Flight Center calculate that every kilometer lost below 520 km substantially increases the propulsion mass required to recover the orbit. Once the telescope falls past 500 km, attitude control in the thinning air becomes an uphill struggle, making precision docking maneuvers exponentially more hazardous.

Commercial Rendezvous: Risk Versus Reboost

This is not NASA’s first time flirting with a private rescue. Between 2022 and 2024, the agency completed a joint feasibility study with private industry, including exploration with SpaceX and the Polaris Program, to assess whether a crewed or uncrewed Dragon capsule could rendezvous with the telescope.

That effort was put on ice when agency risk assessors flagged serious technical challenges. Plume impingement from commercial thrusters risked contaminating Hubble’s delicate mirrors and fragile solar arrays. Furthermore, Hubble lacks modern automated docking targets or lidar reflectors, forcing any approaching vehicle to rely on relative navigation and custom soft-capture hardware.

satellite servicing spacecraft docking test facility — Photo by Jeremy Straub on Unsplash

Yet the calculus in commercial rendezvous has shifted rapidly over the past two years. Startups and defense contractors specializing in future tech satellite servicing platforms have demonstrated optical proximity operations and robotic grapple mechanisms in low Earth orbit. NASA’s new solicitation specifically emphasizes autonomous, uncrewed platforms capable of mating with the SCM without disturbing the telescope’s external insulation blankets.

The agency has divided the RFI into two distinct capability paths:

1. Reboost Architecture: An autonomous servicer docks with Hubble and fires low-thrust electric or chemical propulsion over several weeks to lift the perigee back above 600 kilometers, adding 15 to 20 years to its orbital lifetime.
2. Disposal Architecture: A single-purpose deorbit module grapples the SCM, stabilizes the tumbling structure, and conducts a targeted retrograde burn to ensure surviving titanium structural members hit the open ocean.

Both paths present non-trivial dangers. An autonomous vehicle colliding with the aft ring could tear away the high-gain antennas or send the telescope spinning into an unrecoverable tumble, instantly ending one of the most celebrated runs in the history of observational astronomy, as documented in the telescope’s extensive archive on Wikipedia.

The Closing Window

NASA leadership has repeatedly stated that commercial rescue proposals must come with private capital backing or modest agency cost-sharing; NASA’s science budget cannot absorb a bespoke billion-dollar servicing project while funding the Roman Space Telescope.

Yet letting Hubble burn blindly is politically and operationally unviable. An uncontrolled re-entry of a bus weighing more than eleven metric tons poses an unacceptable debris casualty risk under federal space safety standards.

By reopening the door to commercial contractors, NASA is acknowledging that its options have narrowed. The agency either entrusts its most famous scientific asset to an autonomous commercial docking mission, or it contracts a garbage collector to drive it into the sea. With Hubble’s altitude slipping week by week, that decision can no longer be deferred.