I stumbled across a story today of an instrument that I should have known about but that had undergone a name change. It was first referred to as the WFIRST, Wide Field Infra Red Space Telescope, a long but descriptive name for its mission. It was recently renamed the Nancy Grace Roman Space Telescope by NASA; the name pays tribute to the late NASA executive and first Chief Astronomer who was one of the driving forces in getting the Hubble Space Telescope program through its hurdles.
The telescope was named in a poll of astronomers as the next most important space telescope behind the James Webb Space Telescope. Why? The old name said wide field and that's the telescope's feature.
That graphic gives the impression that the NGRST can capture 2,000 square degrees of sky in one shot, compared to 1.6 sq. degrees from the Hubble Space Telescope. That's not quite right. The NGRST's field of 2,000 degrees divided by the 1.6 of the HST says NGRST is 1,250 times bigger. The NGRST website's FAQ says it's field of view is 100 times larger:
It has a primary mirror that is 2.4 meters in diameter (7.9 feet), and is the same size as the Hubble Space Telescope's primary mirror. The mirror has the same sensitivity as Hubble’s primary mirror but will only be one fifth the weight, showcasing an advancement in telescope technology. It will have the sensitivity and resolution comparable to Hubble, but with a field of view 100 times larger, combining excellent image quality with survey power.
Like the JWST, the NGRST will be sent to orbit around the L2 Lagrange point, about 930,000 miles away from earth in the direction radially away from Earth. The mission is focused on the search for dark matter, dark energy and exoplanets, and will only carry two instruments:
The Roman Space Telescope will have two instruments, the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI) technology demonstration. The WFI provides wide field imaging and spectroscopy, with performance characteristics optimized for cosmology and exoplanet surveys. The CGI provides high contrast imaging and spectroscopy for observations of exoplanets and debris disks. The WFI is a 288-megapixel multi-band near-infrared camera, providing a sharpness of images comparable to that achieved by the Hubble Space Telescope over a 0.28 square degree field of view, 100 times larger than that of Hubble. The Coronagraphic Instrument is a high-contrast, small field of view camera and spectrometer covering visible and near-infrared wavelengths using novel starlight-suppression technology.
The target date for launch is currently set for May of '27 and they claim to be on schedule. It seems to be a much simpler mission from the technology standpoint than JWST was. Where I ran into the NGRST's story was by reading on Twitter that United Launch Alliance had not bid on the contract to launch the mission. Apparently NASA has a rule that when they select the launch vehicle for a high-value spacecraft, the launch vehicle has to be certified at the day of selection. ULA is switching to their Vulcan rocket for payloads of this size, but the first Vulcan hasn't been built yet. At this point, it appears the only vehicle capable of launching the telescope would be the Falcon Heavy.
Rendering of NGRST, from NASA.
There is no dark matter.
ReplyDeleteI don't see any dark matter (sorry... had to)
DeleteSeriously - I've seen some of those reports and it seems like something is wrong with the Standard Model with dark matter and dark energy.
On the other, other hand, while I find it interesting, finding out esoteric details in a field of science is a pretty poor use of taxpayer money.
They say the reason the budget can't be cut is everyone says to cut until it hits their favorite expenditure. I crossed that bridge years ago. Cut NASA, cut it all.
When you look up into the sky at night, it's not an actual universe out there -- it's just scenery projected on the walls of the zoo cage. Like movie special effects, you're supposed to just glance at them in passing, not pick them apart.
ReplyDeleteDark Matter Matters?
Something to look forward to I love falcon heavy
ReplyDeleteIt seems odd to me that an expensive space telescope has only 2 instruments... They are severely limiting what it can do and what future missions it could add.
ReplyDelete