Astra is preparing to launch the first of three consecutive NASA-dedicated missions this weekend from Cape Canaveral to deploy six shoebox-sized hurricane research satellites, helping to create a new mission paradigm. more risky but less expensive science.
The commercial launch company, geared towards the burgeoning small satellite industry, last year won a $7.95 million contract to launch NASA’s six TROPICS spacecraft into orbit using three rockets .
The first of three TROPICS missions is scheduled to lift off during a two-hour window opening at 12 p.m. EDT (1600 GMT) on Sunday. Forecasters are predicting stormy weather at the launch site, with more than a 50% chance that conditions will prevent liftoff. Conditions are expected to improve on Monday, according to the official launch weather forecast.
Astra delivered the rocket to Florida’s space coast last month from its California factory, then conducted a test-firing of the booster’s five engines at Space Launch Complex 46, a commercially operated facility near the furthest expanse. east of Cape Canaveral Space Force Station.
The first two TROPICS satellites are mounted inside a deployer on top of the 43-foot-tall (13.1-meter) Astra launch vehicle, which the company calls Rocket 3.3, or tail number LV0010.
“We’re trying to improve observations of tropical cyclones,” said William Blackwell, principal investigator of MIT Lincoln Laboratory’s TROPICS mission. “And what we’re really trying to characterize is the fundamental thermodynamic environment around the storm. So it’s things like temperature, the amount of humidity and intensity of precipitation, and the structure around the storm.
“These are important variables because they can be linked to the intensity of the storm, and even the potential for future intensification,” Blackwell said Friday in an interview with Spaceflight Now. “So we try to do these measurements with a relatively high revisit. That’s really the key new feature that the TROPICS constellation provides, it’s a better storm revisit.
“We’ll have six satellites in orbit, and one satellite will work to get a nice picture of the storm, and then the next satellite will orbit closely behind it about an hour late,” Blackwell said. “So we’ll have, about every hour, a new image of the storm, and that’s about five to eight times better than what we’re getting today. With these new, rapidly updated image measurements, we hope that it will help us better understand the storm and ultimately better predict the hurricane’s track and intensity.
TROPICS stands for Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats. The mission has a total cost of around $30 million, according to NASA.
Each TROPICS satellite has a single instrument. A microwave radiometer, the size of a coffee cup and rotating 30 times per minute, will create images of tropical cyclones, collect temperature measurements and collect vertical profiles of humidity in the atmosphere.
“I I love TROPICS, just because it’s a bit of a crazy mission,” said Thomas Zurbuchen, chief science mission director at NASA. “Think of six CubeSats doing science, watching tropical storms with a repeat time of 50 minutes.”
“NOAA and the Europeans and many others have been using passive microwave radiometers for decades, and they’re big, expensive instruments,” Blackwell said. “What we’ve done with TROPICS is miniaturize the electronics to make it much smaller.
“The whole satellite for TROPICS, one of them weighs about 10 pounds and is about the size of a loaf of bread,” Blackwell said. “So they’re relatively inexpensive to build and test, and we can make them quite quickly, and they’re relatively inexpensive to launch.”
The TROPICS satellites were built by Blue Canyon Technologies in Boulder, Colorado. Their small size makes them a good fit for Astra, which can deliver around 110 pounds (50 kilograms) of payload into a 310-mile-high (500-kilometer) orbit. Astra’s rocket is the smallest orbital-class launcher currently in flight.
Astra will launch two TROPICS satellites at once, performing missions several weeks apart. If all goes well, launches should be complete by the end of July.
The satellites will launch into orbit 550 kilometers above Earth, circling the planet at an angle of 29.75 degrees from the equator. The low-inclination orbit will focus TROPICS observations on tropical cyclone development hotspots.
The second and third TROPICS launches – currently scheduled for late June and mid-July – will aim to deploy the next four satellites into precise orbital planes, giving the constellation the proper spacing to allow regular cyclone flybys.
Many CubeSats travel to space in carpool launches, allowing operators to take advantage of reduced costs by consolidating their payloads onto a single large rocket. But TROPICS satellites need dedicated launches to reach their precise orbital destinations.
“We want to space out spacecraft as much as possible and keep them above the tropical cyclone belt,” Blackwell said. “This global setup allows us to do that, but it requires three separate dedicated launchers.”
Astra beat out bids from SpaceX, Rocket Lab, Virgin Orbit and Momentus largely due to their lower cost proposition, according to NASA.
“NASA chose Astra because of our unique ability to reach three different orbital aircraft in a very short time, at low cost,” said Martin Attiq, Chief Commercial Officer of Astra. “So to be able to pitch three different times for $8 million is unprecedented.”
Founded in 2016, Astra ultimately aims to launch daily missions to carry small satellites into orbit for a range of customers, including the US military, commercial companies and NASA. The company managed to reach orbit in two of the six trials.
Astra’s most recent flight in March marked the first time the company has placed functioning satellites into orbit, after lifting off from Kodiak Island, Alaska. Astra’s previous launch in February, which left Cape Canaveral, failed to place a payload of NASA-sponsored CubeSats into orbit.
NASA officials are aware of the risk of flying satellites on a relatively untested new launch vehicle. TROPICS is part of NASA’s Earth Venture program, a series of low-cost missions designed for Earth science research. NASA assumes more risk for Venture-class missions.
“Only four of the spacecraft have to work, so two rockets have to work,” Zurbuchen said. “It’s a different level of risk than what we do in so many other things where we focus on, smooth out the risk and reduce it as much as possible. And it’s deliberate. It’s deliberate because the speed is important when you’re in the innovation game, and we want new capabilities, new assets, and new tools.
NASA selected TROPICS for development in 2016.
“We designed the mission from the ground up to build in some robustness to failure,” Blackwell said. “The choice of six satellites was made to give us some leeway. We only needed four to meet our baseline requirements, so we could tolerate satellite failures or launch failures, or whatever, and we could still meet our requirements.
Astra’s first launch with two TROPICS satellites will begin with the ignition of Rocket 3.3’s five kerosene-fueled engines at pad 46. Delphin engines will propel the launch vehicle off the pad with 32,500 pounds of thrust, propelling the rocket upward east- northeast of Cape Canaveral.
Shutdown of the first-stage engine is scheduled for three minutes after liftoff, followed by separation of the rocket payload fairing, which covers the upper stage and TROPICS payloads during climb through the atmosphere. Then the rocket booster stage will jettison to fall into the Atlantic, allowing the upper stage to ignite for five minutes to accelerate to orbital speed.
The deployment of the TROPICS satellites is scheduled for T+plus 8 minutes, 40 seconds, according to a mission schedule published by Astra.
Satellites will deploy solar panels to begin generating electricity, and ground crews will operate the TROPICS spacecraft through testing and verification.
If all three TROPICS launches lift off as planned, the satellites should all be collected by August, just in time for the peak of the Atlantic hurricane season, according to Will McCarty, NASA program scientist for the mission. The mission is designed for at least one year of scientific observations.
“We’re, of course, very motivated to get the data as soon as possible because we’re going to be in the throes of the Atlantic hurricane season, so there’s going to be a lot of demand for that data,” Blackwell said. .
A pathfinder satellite for the TROPICS mission launched last June as part of a SpaceX rideshare mission and performed well in orbit, collecting temperature and humidity test measurements from several tropical cyclones, including the Hurricane Ida before it makes landfall in Louisiana.
Experience with the TROPICS pathfinder satellites builds confidence that the six operational satellites will work, McCarty said.
“Our requirement from NASA is to collect science data for a year, and we hope to go longer than that,” Blackwell said. “There are cases where these CubeSats last three years or even longer, so we hope it will be much longer than the one-year requirement.”
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