Avoiding an uncontrolled reentry; boost Hubble and keep the science – Isaacman

3 min read · reported by NASASpaceflight

NASA Administrator Jared Isaacman has addressed the ongoing debate about the Hubble Space Telescope’s long-term future after the agency issued a Request for Information seeking commercial options for a reboost, servicing, or controlled deorbit.

The RFI, open through the end of November, comes as Hubble continues to operate on a reduced set of gyroscopes more than 16 years after its final Space Shuttle servicing mission.

Isaacman, speaking to NSF during the Flame Trench show, said an uncontrolled reentry is not acceptable and that any funded visit should prioritize extending the observatory’s science return.

“I certainly, you know, had various ideas of how it could have been addressed years ago,” Isaacman said. “NASA was very involved in that.”

He added that earlier commercial concepts, including his own Polaris Program proposal that NASA studied and ultimately did not pursue in 2024, had been evaluated at the time.

The equation has since shifted as commercial capture and servicing capabilities have matured.

Shuttle history and the final servicing

Hubble was launched on STS-31 in April 1990 aboard Discovery.

The launch of Space Shuttle Discovery (STS-31) on April 24, 1990, the other shuttle sitting on the adjacent launch pad was Space Shuttle Columbia (preparing for the upcoming STS-35 mission).

Five subsequent Space Shuttle servicing missions repaired and upgraded the telescope, with the final one, STS-125 / Servicing Mission 4, flown by Atlantis in May 2009.

That mission installed the Wide Field Camera 3 and Cosmic Origins Spectrograph, replaced gyroscopes and batteries, and added a soft-capture mechanism.

Because Hubble’s orbit offered no safe haven at the International Space Station, Endeavour stood ready on the adjacent pad as the STS-400 Launch On Need rescue mission throughout the flight.

The hardware and systems installed in 2009 are now aging. Hubble is currently operating with two functional gyroscopes out of six and has shifted to single-gyro mode.

This change has reduced available observation time by roughly 12 percent and limits the telescope’s ability to track certain targets, yet the observatory continues to fill a unique role in optical and ultraviolet astronomy.

Hubble during Endeavour’s STS-61 servicing mission

Demand for Hubble observing time remains high. Even with reduced capabilities, the telescope continues to deliver science that cannot yet be fully replaced by other facilities, and astronomers continue to compete for every available orbit.

Without a propulsion system of its own, atmospheric drag is expected to bring the telescope down in the 2033–2034 timeframe. The soft-capture mechanism installed on STS-125 was intended to support a future robotic or crewed deorbit, though no such mission has been baselined.

Risk, learning, and next steps

Isaacman pointed to NASA’s recent attempt to reboost the Swift telescope as useful operational experience even though that effort did not succeed.

“That was absolutely a risk worth taking,” he said. “They learned from that. NASA learned from that, too. I’m sure that better equips them and others to potentially do it.” In respect to Hubble’s end-of-life requirements, Isaacman was more direct.

“Hubble, you can’t let it have an uncontrolled re-entry. That would not be the right thing to do. If you’re going to spend money to go up there and do something, you might as well boost it, get as much science as you possibly can out of it.”

Looking further ahead, Isaacman left open the possibility of eventually recovering Hubble for display. This goal is no longer a wild dream thanks to the incredible capability provided by SpaceX’s Starship vehicle.

— Elon Musk (@elonmusk) July 24, 2021

“I wouldn’t rule out the possibility that well into the future somebody could go and get it and bring it back and put it in a museum. I think that would be one of the greatest artifacts in the Smithsonian. I mean, just be so cool.”

However, for now, the RFI seeks input on three paths: a reboost to delay reentry, a servicing mission that could restore or expand capabilities, or a controlled end-of-life disposal. Responses are due by the end of the month.

(Featured Image: The Hubble Space Telescope – via NASA)

Reported by NASASpaceflight. Reproduced unedited by Everything Space. View the original →