Hubble returned to operational service, showcases exoplanet’s second atmosphere

The Hubble Space Telescope recently garnered headlines for a software anomaly that caused the iconic… The post Hubble returned to operational service, showcases exoplanet’s second atmosphere appeared first on NASASpaceFlight.com.

Hubble returned to operational service, showcases exoplanet’s second atmosphere

The Hubble Space Telescope recently garnered headlines for a software anomaly that caused the iconic observatory to enter safe mode as its control teams worked to successfully restore the telescope to operational status.

While Hubble is showing its age, scientists using the observatory are nonetheless continuing to produce incredible scientific discoveries, including a recent announcement surrounding an exoplanet 41 light years away that is on its second atmosphere.

Hubble issues

In May 2009, Space Shuttle Atlantis performed the fifth and final servicing mission to the Hubble Space Telescope, which was already showing signs of degradation in the seven years that had passed since its previous upgrade.

Now 12 years on from that final servicing mission, the telescope is showing its age again, most recently with a safe mode event that occurred on Sunday, 7 March at 04:00 EST/09:00 UTC when a software error was detected inside the telescope’s main computer. 

Hubble’s control teams quickly isolated the cause of the error to a recent upload to help the telescope compensate for fluctuations in one of its gyroscopes — which are themselves vital to the rock-solid pointing ability of the observatory.

Moreover, a different issue stemming from the safe mode revealed another issue with the telescope, specifically with its aperture door.  This door must remain open for scientific observations, but is designed to close in the event the telescope enters safe mode.  This is done to protect the sensitive optics packages from potential damage if the telescope were to drift to a Sun-pointing orientation. 

However, the safe mode event of Sunday, 7 March did not result in the aperture door closing, which led teams down a failure analysis which revealed that the primary motor that closes and opens the door was no longer working. 

Control teams switched to the backup motor and were able to verify proper operation of the aperture door.  The backup motor will now serve as the primary motor.

By Saturday, 13 March, Hubble was back in full operation as teams reactivated Wide Field Camera 3 — the last of the instruments to be brought back online.

Nonetheless, the iconic telescope is aging, and the day will come when a failure will present itself.  A failure which cannot be overcome.

The telescope was designed to be serviced and upgraded by the Space Shuttle fleet.  Without that lifeline, the observatory’s remaining time will be determined by the continued operations of its systems.

Atmospheric drag is also lowering Hubble slowly over time.  Unless the spacecraft were to be re-boosted, it will naturally reenter the atmosphere sometime in the 2030s — with the exact date dependent on solar activity, which affects the thickness of Earth’s atmosphere and thus the drag imparted to Hubble that lowers its altitude.

Hubble, seen from the crew cabin of the Space Shuttle. (Credit: NASA)

While unlikely, the possibility remains that a Crew Dragon or Orion mission could service the telescope again.  

In June 2020, John Grunsfeld, former astronaut/Hubble servicing spacewalker and former associate administrator for NASA’s Science Mission Directorate, encouraged a study on a such a mission, saying: “I wouldn’t preclude the possibility, because we have the capability coming online in the next ten years, that you could send a repair mission up to Hubble. We have the technology to go back to Hubble.”

The remarks were not official, though Grunsfeld did present notional mission architecture for such a flight.

Of note, neither NASA nor SpaceX (the only two organizations currently with spacecraft to perform such a mission – Orion being NASA’s internal ship and Crew Dragon from SpaceX being the only currently operational crew orbital transportation vehicle for the U.S.) have made any comment regarding a feasibility study or a potential future mission to Hubble.

An exoplanet on its second atmosphere?

Just 41 light years away lies a 4.5 billion year old, Earth-sized, terrestrial world called GJ 1132 b.  

For Earth-like exoplanet hunters, that’s where the excitement ends.  However, to others in the exoplanet field, that’s where the excitement begins.

Because this exoplanet is nothing like Earth.  It orbits its host star every 1.5 days and is tidally locked with that star (a red dwarf).  What’s more, when scientists used the Hubble Space Telescope to examine this exoplanet, they discovered an atmosphere composed of molecular hydrogen, hydrogen cyanide, methane, and aerosol haze.

Artist’s impression of GJ 1132 b. (Credit: NASA, ESA, and R. Hurt (IPAC/Caltech))

Not exactly something a human would want to breathe, but the simple fact the GJ 1132 b has an atmosphere is what makes the exoplanet so fascinating.  Because it wasn’t expected to have one. 

“We first thought that these highly irradiated planets could be pretty boring because we believed that they lost their atmospheres,” said Raissa Estrela of NASA’s Jet Propulsion Laboratory (JPL), co-author of the study to be published in a forthcoming issue of The Astronomical Journal.

“But we looked at existing observations of this planet with Hubble and said, ‘Oh no, there is an atmosphere there.’  It’s super exciting because we believe the atmosphere that we see now was regenerated, so it could be a secondary atmosphere.”

Based on observations from Hubble and current models and theories of planetary formation, GJ 1132 b likely began life as a several-times Earth diameter gaseous planet, falling into a category known as sub-Neptune.

The massive planet’s atmosphere was quickly irradiated by its host star in a short period of time that left behind the planet’s terrestrial core that is roughly the same size as Earth.

So if its atmosphere was stripped away by its star’s radiation, how does it have an atmosphere today?

The terrestrial rock, or core of the gas giant, left behind after its atmosphere was removed, is significantly affected by a process known as tidal heating, where the gravitational tugs of war between the red dwarf star and at least one other exoplanet in the system on GJ 1132 b cause it to expand and contract — which in turn transfers that energy into the planet’s core in the form of heat which sustains a molten interior.

Containing that interior is a much cooler and very thin crust — so thin that it cannot support volcanic structures, meaning the exoplanet’s surface is likely cracked like an eggshell.  Those cracks allow the release of hydrogen and other gases.

The planet’s gravity then keeps those gasses contained: the atmosphere observed today.

“How many terrestrial planets don’t begin as terrestrials?” asked Mark Swain of JPL, lead author of the paper.  “Some may start as sub-Neptunes, and they become terrestrials through a mechanism that photo-evaporates the primordial atmosphere.”

While Hubble itself is not powerful enough to directly image the exoplanet, an upcoming NASA observatory, the James Webb Space Telescope, does possess the ability to observe GJ 1132 b in finer detail, specifically in the infrared band which may allow scientists to see the exoplanet’s surface as well as potential magma pools or active volcanism.

The James Webb Space Telescope is currently undergoing final testing and check out at Northrop Grumman’s Redondo Beach, California facility near Los Angeles.  It will be shipped to its launch site in the coming months and currently remains on track for liftoff on top of an Ariane 5 rocket from Kourou, French Guiana in South America on 31 October 2021.

(Lead image credit: NASA)

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Starship SN11 prepares to fly as SpaceX pushes for Orbital flight this summer

Starship SN11 is preparing to conduct a Static Fire test Monday ahead of a potential… The post Starship SN11 prepares to fly as SpaceX pushes for Orbital flight this summer appeared first on NASASpaceFlight.com.

Starship SN11 prepares to fly as SpaceX pushes for Orbital flight this summer

Starship SN11 is preparing to conduct a Static Fire test Monday ahead of a potential flight as early as Tuesday. Forever subject to change due to numerous considerations – ranging from weather, hardware parameters, and paperwork approval – SN11 will mark the final test of this iteration of Starship before the program moves into the next phase of testing.

Following SN11’s flight, SpaceX will move on to SN15, 16, and 17, alongside testing with Super Heavy prototypes BN1 and BN2, before shooting for an orbital launch with SN20 and BN3. In typical SpaceX-style, that orbital launch has an astonishing – and unlikely – “by July 1” target. At the very least, this target portrays SpaceX’s Starship drive to push the vehicle into operation.
SN11:

Starship SN11 Updates
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  • This will be the fourth high altitude test flight of the prototype Starship, and while efforts continue to focus on refining the landing element of the flight profile, the vehicle has already achieved numerous milestones, including proving long-duration Raptor performance and controllability during ascent and the stable “bellyflop” return under the control of its aero surfaces – a huge test flight objective.

    SpaceX Boca Chica, meanwhile, has pumped out Starships with such high cadence as to allow for fast turnarounds after each launch, implementing tweaks to the vehicle ahead of the next flight.

    SN8 achieved the flip maneuver before losing thrust due to the Methane (CH4) Header Tank losing pressure during the landing burn, SN9 did not complete the flip due to engine relight issues, and SN10 completed all the maneuvers before landing hard – eventually resulting in the vehicle exploding several minutes after touchdown.

    The mitigation path for these issues focuses on those final few seconds of flight.

    Post SN8, SpaceX opted to add helium pressurization to SN9’s CH4 Header Tank. After SN9’s engine relight issue, SpaceX opted to light all three engines during SN10’s flip and burn before deselecting the engine “with the least lever arm” in the event all three successfully relit.

    Indeed, all three engines did relight during SN10’s flip before the system deselected to land on just one engine. While the landing velocity looked visually acceptable, SpaceX CEO and Chief Designer Elon Musk soon confirmed it was still too high.

    Additionally, a few of the landing legs did not lock into place, although Elon noted the high velocity landing would have seen them squashed regardless. Notably, Elon noted the hard landing was due to the Raptor – conducting the landing burn -ingesting helium that was pressurizing the CH4 Header Tank.

    It’s not clear what refinements are being made for SN11’s flight, other than Elon’s comment that multiple fixes are in work.

    One change likely during SN11’s landing is the use of two engines instead of down-selecting to just one as a way to counter potential loss of thrust and increase redundancy during the no-room-for-failure landing burn.

    Regardless of flight changes, SN11’s test campaign during its pad flow has so far been going mostly to plan, with proof testing already complete under both ambient and cryogenic conditions.

    The Static Fire test was expected by the end of last week. However, issues – understood to be related to GSE (Ground Support Equipment) – delayed the firing of SN11’s Raptors, with the weekend not available for testing due to the requirement to close Highway 4 during such tests. SpaceX only requests a handful of weekend road closures to keep local disruption to a minimum.

    The latest Static Fire window is set for Monday morning, with the potential to launch the following day. However, this is pending acceptable weather conditions.

    The FAA (Federal Aviation Administration) formally authorized the SN11 flight, as reported from the Washington Post’s Christian Davenport on Monday.

    Future Vehicles:

    Following the launch of SN11, SpaceX will move on to Starship SN15 – bypassing SN12, 13, and 14 – as previously reported by NASASpaceflight.com.

    SN15 includes a new Thrust Puck design and other – mostly unknown – improvements. It will likely sport additional Thermal Protection System (TPS) as part of the heatshield test program.

    This vehicle is currently in the Mid Bay, awaiting its turn to enter the High Bay for nosecone stacking. Currently, the High Bay is occupied by the two large tankage sections for the first Super Heavy prototype, BN1.

    BN1 is not expected to fly. Instead, it will be stacked and rolled to the Starship suborbital pad for ground testing, including a potential Static Fire test. This will provide vital data ahead of the test flight of BN2, of which sections have already been spotted waiting for stacking.

    The BN1 test campaign is expected to occur before SN15 goes to the pad for its test flight.

    Once SN15 enters its pad flow, this will mark the start of what is likely to be a new test campaign involving three Starships, with SN16 and SN17 joining.

    According to documented information seen by NASASpaceflight, BN1, BN2, and the new Starships represent “iterative improvements to the vehicles to improve the design and serve as production pathfinders” to aid the increasing production cadence.

    It is also possible that SpaceX will skip further production of the SN18 and SN19 Starships based on those vehicles not being referenced. This would match how SN12, 13, and 14 were also scrapped as SpaceX opted to advance from SN11 to SN15.

    Notably, the information seen by NASASpaceflight – and always subject to change – also adds a fascinating note about the first orbital flight, which is cited as involving Super Heavy BN3 and Starship SN20, “with a goal to get to orbit by July 1”.

    While that date is highly ambitious at best, it proves SpaceX’s drive to send Starship into orbit “this year” as an absolute target.

    This goal is also backed up by visual work taking place both on the vehicles and at the launch site.

    With TPS application on patches of current Starships being used to test how the material and its attach points react during prop loading and flight stresses, entire sections of future Starships are being covered in the hexagon tiles.

    This process – covering the vehicle’s entire windward side – will be required for missions that will see Starships return from space and endure reentry heating.

    It is also entirely possible that a Starship ahead of SN20 will receive a large amount of TPS to increase performance data before SN20’s flight into space.

    A huge amount of work is also taking place over at the Orbital Launch Site.

    This site will eventually host two Super Heavy mounts, with the first already waiting for its launch table and the construction of a huge integration tower that will include a crane to lift and mate Starship with the booster while on the mount.

    Just last week, the first of the new propellant tanks arrived at the launch site, ready to quench the thirst of future Super Heavy boosters.

    The aforementioned information also noted that the Orbital Launch Pad would indeed be capable of catching the booster in lieu of having landing legs, as previously noted by Elon on social media. This would involve catcher arms on the Integration Tower. This is unlikely to be ready in time for BN3’s flight, if SpaceX continues to target BN3 for the orbital mission, given plans are continually changing at SpaceX Boca Chica.

    Despite the impressive construction pace at the launch site, being ready for a BN3/SN20 launch “by July 1” can be all-but ruled out. However, with the Integration Tower potentially a week or so away from rising out of the ground, the potential of an orbital mission later this year is now becoming almost a certainty.

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