The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission will provide rapid-refresh microwave measurements over the tropics that can be used to observe the thermodynamics of the troposphere, and precipitation structure for storm systems at the mesoscale and synoptic-scale over the entire storm lifecycle.

Three launches will place the six satellites in pairs across three slightly different low-Earth orbits, all at an angle near 30 degrees above the equator. This will maximize the amount of time the satellites spend passing over the part of Earth where most tropical cyclones form – a horizontal band stretching from about the Mid-Atlantic region of the United States to the southern coast of Australia, roughly between 38 degrees north and south latitudes. Ideally, one of the TROPICS satellites will pass over any given area within that band about once an hour.

All matter – including water vapor, oxygen, and clouds in the atmosphere – emits energy as heat and light, a phenomenon known as Plancks Law. Each of the TROPICS satellites has an instrument called a microwave radiometer that measures these atmospheric emissions.

The microwave radiometer aboard each TROPICS satellite measures microwave frequencies ranging from about 90 to 205 gigahertz. These frequencies tell scientists about the temperature, precipitation, moisture and other characteristics of the storm and surrounding atmosphere. The amount of heat and light – or radiance – at these frequencies comes from different altitudes, allowing the TROPICS satellites to create three-dimensional images of the cyclones’ environments. The frequencies TROPICS uses are also very sensitive to characteristics of ice and clouds, which will help meteorologists study how tropical cyclones develop and intensify.

Science Goals:

• Relate precipitation structure evolution, including diurnal cycle, to the evolution of the upper-level warm core and associated intensity changes
• Relate the occurrence of intense precipitation cores (convective bursts) to storm intensity evolution
• Relate retrieved environmental moisture measurements to coincident measures of storm structure (including size) and intensity
• Assimilate microwave radiances and/or retrievals in mesoscale and global numerical weather prediction models to assess impacts on storm track and intensity

The first stage performed successfully, however the upper stage engine did not shut down early, and failed to deliver the payload to orbit. Two of six previous Astra orbital attempts have succeeded.

Courtesy of NASA

Image credit: Blue Canyon Technologies

Meet Rocket 3, Astra's entry to the dedicated, small satellite launch market.

Capable of lifting 500-630 kg to low Earth orbit and taking up to 335 kg to sun-synchronous orbit, Rocket 3 is made up of two stages.

The first stage uses 5 Delphin engines while the second stage uses a single Aether engine. Both stages use RP-1 kerosene and liquid oxygen.

The entire rocket is designed for rapid deployment and only needs about 1 week of launch site preparation. Rocket 3 can be launched from any location and does not require a preexisting spaceport or launch range.

The entire rocket and all of its ground systems are delivered in shipping containers to the launch location making it especially versatile and able to launch in Alaska or Florida.

Through Astra’s Rocket 3 lineage, there have been 4 variations starting with Rocket 3.0.

The first Rocket 3, "1 of 3" or "Rocket 3.0", was to be launched in late February and early March of 2020 as part of the DARPA Launch challenge. On March 23rd, 2020 Rocket 3.0 was destroyed by fire during launch preparations while Astra was detanking fuel during a pre-launch countdown dress rehearsal. No payloads were on-board at the time of the incident.

A second launch attempt took place on September 12th, 2020 using the second Rocket 3 vehicle, Rocket 3.1. The launch failed during first stage flight, when Rocket 3.1 experienced an anomaly and fell back to Earth shortly after, and exploded on impact.

On December 15th, 2020, Astra launched its third Rocket 3 vehicle, Rocket 3.2. The rocket successfully passed the Kármán Line and reached its target orbital altitude of 390 kilometers, a first for Astra. However, due to issues with the upper stage's fuel mixture, the rocket failed to achieve orbit.

On August 28th, 2021, Astra launched its fourth Rocket 3 vehicle, Rocket 3.3 (serial number LV0006). The flight carried an instrumentation payload for the United States Space Force under the Space Test Program. Shortly after liftoff, a single engine failure caused the vehicle to drift horizontally off the launch pad before ascending vertically. The vehicle deviated from its licensed trajectory and range safety terminated the flight at approximately T+02:28. The rocket reached a peak altitude of 50 km (31 mi) before crashing into the ocean downrange of the launch site.

On November 20th, 2021 Astra's Rocket 3.3 vehicle (serial number LV0007) successfully reached orbit after launching from Pacific Spaceport Complex – Alaska carrying the demonstration payload STP-27AD2 (COSPAR 2021-108A, SATCAT 49494) for the United States Space Force.

On February 10th 2022, Astra Rocket 3.3 (serial number LV0008) experienced an anomaly post-launch, during stage separation. After two previous scrubbed launch attempts, ignition and launch of LV0008 occurred nominally. First stage separation failed, and second-stage ignition occurred erratically. The anomaly caused the second stage to spin out of control, and the payload was lost.

Astra is currently developing an upgraded variant of Rocket 3 called Rocket 4. This upgraded design contains new higher performance first stage engines and a payload capacity of several hundred kilograms to low Earth orbit. The first Rocket 4 launch is expected in 2022.

In September 2020, Astra submitted a proposal to the Air Force's AFWERX program titled, "Responsive Launch Enabled by Astra's Rocket 5.0". Rocket 5 will be a variant of the Rocket 3 dedicated to suborbital point-to-point delivery, featuring a modified second stage between the Rocket 3's first and upper stages.

Image: John Kraus for Astra

This storied launchpad had its first launch in 1987 and was originally used for tests of the Trident II missile between 1987 and 1989. Following the completion of the Trident's land-based tests, the complex was deactivated.

In 1997, Space Florida began operations at the site and was opened for commercial space operations. Lockheed Martin launched an Athena II and an Athena I from the pad in 1998 and 1999 respectively.

In March 2010, the USAF 45th Space Wing issued Real Property Licenses to Space Florida for Launch Complexes 36 and 46 at Cape Canaveral Air Force Station.

On July 1, 2010, the Federal Aviation Administration approved a Launch Site Operator's License for commercial launches at Launch Complex 46.

In July 2015, the U.S. Air Force and Orbital ATK announced a Minotaur IV launched from SLC-46 that would be used for the ORS-5 mission in 2017.

On July 2, 2019, NASA launched a repurposed Peacekeeper missile from SLC-46, carrying the Orion spacecraft for the Ascent Abort-2 mission.

Astra began launching from SLC-46 in January of 2022. They are planning for a launch cadence of once a month for 2 years.

Photo: John Kraus for Astra