I’m skeptical. Probably that is being misunderstood. SpaceX now offers the extended fairing as a pre-developed option since they’re already developing it for another payload(a).
I’m skeptical. Probably that is being misunderstood. SpaceX now offers the extended fairing as a pre-developed option since they’re already developing it for another payload(a).
Perhaps the deployable aperture cover, when stowed, decreases the launch configuration length to fit within standard fairing.
In still skeptical, as well.
Time will tell.
NASA’s Roman Space Telescope’s ‘Eyes’ Pass First Vision Testhttps://www.nasa.gov/wp-content/uploads/2024/04/ota-harris-240402-004-copyrevb.jpgEngineers at L3Harris Technologies in Rochester, New York, have combined all 10 mirrors for NASA’s Nancy Grace Roman Space Telescope. Preliminary tests show the newly aligned optics, collectively called the IOA (Imaging Optics Assembly), will direct light into Roman’s science instruments extremely precisely. This will yield crisp images of space once the observatory launches.
“This is the pre-launch first light, our first time seeing through the entire telescope,” said Joshua Abel, the lead systems engineer for the Roman Space Optical Telescope Assembly at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re excited to enter the next phase of the project!”
Each of Roman’s mirrors had passed individual tests, but this was the first time they were assessed together. Engineers had to make sure light would move through all of the optics in a tightly controlled way, or else the telescope’s images would appear blurred.
“The telescope’s optics are crucial for all of Roman’s future observations,” said Bente Eegholm, an optical engineer working on Roman’s Optical Telescope Assembly at Goddard. “In addition to the large primary mirror and the secondary mirror, eight relay mirrors serve Roman’s two science instruments. All 10 telescope mirrors need to be aligned to well within the width of a human hair in order to optimize the telescope’s imaging quality such that Roman can fully achieve its science goals.”
The meticulous month-long alignment process involved a series of iterations to bring test images into ever-sharper focus. Once the mirrors were all properly situated, technicians permanently locked them in place. Three of the mirrors will still be movable in space thanks to actuators – mechanisms that control the mirrors’ positions – which will allow astronomers to fine-tune the alignment even further once Roman begins its observations.
The IOA’s vision test establishes a baseline for upcoming vibration and acoustic tests. Engineers will compare measurements from before and after those tests to make sure the optics will withstand the strong shaking and intense sound waves during launch.
After that, the IOA will have a final “eye” exam – this time in vacuum conditions at its cold operational temperature. Materials expand and contract with temperature shifts, and Roman’s optics will go from room temperature conditions on Earth to a frigid 9 degrees Fahrenheit (minus 13 degrees Celsius) in space.
“Our prediction of the small change we expect to see going from ambient to these colder temperatures is very important,” Abel said. The test will also measure the IOA’s performance in extremely low pressure to assess how it will operate in the vacuum of space.
“The joint team from L3Harris and NASA has fully achieved the goals of the test,” said Scott Smith, Roman telescope manager at Goddard. “The technicians and engineers have executed a successful optical test with precision and excellence while maintaining their commitments to schedule.”
The entire Optical Telescope Assembly, of which the IOA is a core component, is expected to be complete and delivered to Goddard this fall.
[zubenelgenubi: Attach files. Do not embed them.]
NASA’s Roman Space Telescope’s ‘Eyes’ Pass First Vision Test
https://www.nasa.gov/wp-content/uploads/2024/04/ota-harris-240402-004-copyrevb.jpg
Engineers at L3Harris Technologies in Rochester, New York, have combined all 10 mirrors for NASA’s Nancy Grace Roman Space Telescope. Preliminary tests show the newly aligned optics, collectively called the IOA (Imaging Optics Assembly), will direct light into Roman’s science instruments extremely precisely. This will yield crisp images of space once the observatory launches.
“This is the pre-launch first light, our first time seeing through the entire telescope,” said Joshua Abel, the lead systems engineer for the Roman Space Optical Telescope Assembly at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re excited to enter the next phase of the project!”
Each of Roman’s mirrors had passed individual tests, but this was the first time they were assessed together. Engineers had to make sure light would move through all of the optics in a tightly controlled way, or else the telescope’s images would appear blurred.
“The telescope’s optics are crucial for all of Roman’s future observations,” said Bente Eegholm, an optical engineer working on Roman’s Optical Telescope Assembly at Goddard. “In addition to the large primary mirror and the secondary mirror, eight relay mirrors serve Roman’s two science instruments. All 10 telescope mirrors need to be aligned to well within the width of a human hair in order to optimize the telescope’s imaging quality such that Roman can fully achieve its science goals.”
The meticulous month-long alignment process involved a series of iterations to bring test images into ever-sharper focus. Once the mirrors were all properly situated, technicians permanently locked them in place. Three of the mirrors will still be movable in space thanks to actuators – mechanisms that control the mirrors’ positions – which will allow astronomers to fine-tune the alignment even further once Roman begins its observations.
The IOA’s vision test establishes a baseline for upcoming vibration and acoustic tests. Engineers will compare measurements from before and after those tests to make sure the optics will withstand the strong shaking and intense sound waves during launch.
After that, the IOA will have a final “eye” exam – this time in vacuum conditions at its cold operational temperature. Materials expand and contract with temperature shifts, and Roman’s optics will go from room temperature conditions on Earth to a frigid 9 degrees Fahrenheit (minus 13 degrees Celsius) in space.
“Our prediction of the small change we expect to see going from ambient to these colder temperatures is very important,” Abel said. The test will also measure the IOA’s performance in extremely low pressure to assess how it will operate in the vacuum of space.
“The joint team from L3Harris and NASA has fully achieved the goals of the test,” said Scott Smith, Roman telescope manager at Goddard. “The technicians and engineers have executed a successful optical test with precision and excellence while maintaining their commitments to schedule.”
The entire Optical Telescope Assembly, of which the IOA is a core component, is expected to be complete and delivered to Goddard this fall.
[zubenelgenubi: Attach files. Do not embed them.]
Huh aren’t the mirrors still classified, surprised we get an image?
This mirror assembly shows the amazing advances in optics since Hubble:
100x the field of view
1/4 the mass
8x the surface accuracy (this is 1.2 nm RMS, Hubble was about 10nm)
A much shorter optical assembly (long assemblies reduce abberations)
The field of view and the short optical assembly are due to a three mirror anastigmat design (3 curved mirrors), which in turn depended on advances in mirror fabrication that allow very non-spherical shapes. I think the super smooth surfaces are due to new polishing techniques such as using ion beams for exact figuring. I don't know why it's so much lighter (active correction of a thinner mirror?).
I'd assume the extra polishing work NASA had to do on this mirror was to get the extreme (roughly lambda/500) surface accuracy. I believe this is needed for NASAs coronograph, but would not be needed for spy satellite imagery.
I’m skeptical. Probably that is being misunderstood. SpaceX now offers the extended fairing as a pre-developed option since they’re already developing it for another payload(a).
Hubble is 13.2 meters long and 4.2 meters wide, so it could just about fit in the standard Falcon fairing. And it's clear the new optical system is much shorter than Hubble's (compare the images above to
the Hubble design, recalling the mirrors are the same size). That should save a few meters, and so the Roman observatory could reasonably fit.
I’m skeptical. Probably that is being misunderstood. SpaceX now offers the extended fairing as a pre-developed option since they’re already developing it for another payload(a).
Hubble is 13.2 meters long and 4.2 meters wide, so it could just about fit in the standard Falcon fairing. And it's clear the new optical system is much shorter than Hubble's (compare the images above to the Hubble design, recalling the mirrors are the same size). That should save a few meters, and so the Roman observatory could reasonably fit.
Have you bothered to check the size of the payload envelope of the Falcon 9 standard fairing? HST doesn't fit in there (it is at least 2.3 meters too long and at least 1.5 meters too wide at the top) and Roman, in its stowed configuration, fits only barely.
A couple of snips from the annual GAO report relating to launch. The Roman section is pages 79 & 80 (sheets 88 & 89).
The Roman project continues to operate within its replanned cost and schedule baselines, which were updated in June 2021. The replan set a life-cycle cost of $4.3 billion and a launch readiness date of May 2027. The project is still working to an earlier launch readiness date of October 2026, which was the original baseline date prior to the replan
The project completed a manufacturing readiness review for the flight unit of the Launch Loads Vibration Isolation
System, but the project is tracking a performance risk. The Launch Loads Vibration Isolation System protects the telescope from launch vibrations and spacecraft generated disturbances while on-orbit. This system’s flight isolators are currently a critical path item in the integration and test schedule. If they do not perform as expected, it could result in a schedule delay and increased costs due design changes.
https://www.gao.gov/assets/gao-24-106767.pdf