ESA expertise to support Portugal's launch program

Portugal is developing the infrastructure for a national spaceport on one of the islands of the Azores archipelago, Santa Maria, a European launch and landing location for small satellites. As an ESA Member State, Portugal has requested ESA's tailored expertise and technical assistance in an agreement signed on 21 June by ESA Director General Jan Worner and Manuel Heitor, Minister for Science, Technology and Higher Education.Within its purpose, ESA provides assistance to its Member States for national activities. Portugal will benefit from ESA's leading technical and programmatic expertise in managing launch base development and ground infrastructures, related services, and testing as well as in the application of specific legal frameworks for national spaceports. Portugal Space will retain overall technical and financial responsibility for request and use of ESA expertise. There is a growing demand for launches of small satellites on microlaunchers. As Member States respond to these market needs, ESA intends to lend support to those Member States requesting it, in the domain of spaceports and test infrastructures under their jurisdiction as well as related services. This ESA assistance to Member States is further defined as part of the Commercial Space Transportation Services and Support programme proposed for decision at Space19+ in November.

In 2022, ESA could make use of the Azores landing location for its Space Rider lifting body, which will serve as a laboratory platform in space for extended periods and return to Earth with its cargo. The Azores landing base would be suitable as it allows Space Rider to return at the same latitude as its operational orbit, requiring fewer deorbiting manoeuvres.

Ariane 5 launches T-16 and EUTELSAT 7C satellites

Arianespace confirms its status as a trusted partner to world-class operators of communications satellites with the launch of T-16 and EUTELSAT 7C. The company's fifth launch of 2019 took place on Thursday, June 20 at 6:43 pm (local time) from the Guiana Space Center (CSG), Europe's Spaceport in Kourou, French Guiana. With this latest success, the second with an Ariane 5 launch vehicle in 2019, Arianespace consolidates its leadership in the market for commercial launches into geostationary orbit. This launch was the 104th overall for an Ariane 5 and the 310th launch by the Arianespace family. Following the launch, Stephane Israel, Chief Executive Officer of Arianespace, said: "I would like to thank our two loyal customers for entrusting us with the launch of their T-16 and EUTELSAT 7C satellites. This second Ariane 5 launch of the year reaffirms the reliability of our heavy-lift launcher and its leadership in the geostationary market. We are very proud to count 24 GEO satellites in our order book. Some of them will be launched by Ariane 6, the new-generation launch vehicles scheduled to make its first flight in 2020."Arianespace supports two world leaders in satellite communications - EUTELSAT 7C is the 33rd satellite to be launched by Arianespace for Eutelsat. With this latest launch, Arianespace continues to bolster its exceptional partnership with Eutelsat, a relationship that reaches back to 1983. More than half of the operator's satellites to date have been orbited by Arianespace. This relationship is set to continue, since Arianespace's backlog includes seven more Eutelsat satellites, to be orbited by Ariane 5 and Ariane 6.

Built by Maxar Technologies, EUTELSAT 7C is a high-power broadcast satellite for markets in Africa, Europe, the Middle East and Turkey. By significantly increasing power over Sub-Saharan Africa, it will make room for several hundred additional digital channels to support the region's rapidly expanding television market.

Built by Airbus Defence and Space, T-16 will provide high-power broadcast services to the continental United States, Alaska, Hawaii and Puerto Rico.

Arianespace has 21 more Airbus satellites in its launch backlog.

NewSpace could eliminate Sun-Synchronous orbits

NewSpace is a recently formed movement and philosophy that encompasses a globally emerging private spaceflight industry. This term is generally used in connection with a global private sector of new aerospace companies and ventures. One primary objective is to develop faster, better and cheaper access to space and spaceflight technologies. This movement is thought to be a major driving force in the growing near-Earth space commerce market. The increased traffic from the soon-to-be-launched 15,000 new satellites will have some unexpected consequences. One expected consequence is the demise of the sun-synchronous family of orbits. A sun-synchronous orbit (SSO) is one of the most frequently used orbits for Earth-science and national security missions. SSOs are near-polar orbits whose ascending nodes precess at a rate that is matched to the Earth's mean orbital rate around the sun, i. e., about one degree per day. This motion allows the maintenance of the orbit's geometry with respect to the sun such that solar lighting along the SSO satellite's ground track remains approximately the same over the mission's duration. Thanks to the Earth's asymmetrical gravity field, a natural force is exerted on these orbits that results in precessional motion that assures a constant sun angle as each SSO satellite passes over the Earth's surface. The figure illustrates the relationship between SSO inclination and altitude for circular orbits. For example, one SSO satellite at 800 km altitude would have to have an inclination of 98.6 degrees in order to maintain a constant sun angle with the orbit.

SSOs have been used for more than 50 years. One result of this is the accumulation of a large population of resident space objects (RSO) consisting of active satellites, expired satellites, discarded rocket bodies and many other debris objects.

Thus, the orbital belt between 700 and 900 km altitude is the zone of highest debris population and is becoming so congested that flight threats in this region are approaching critical levels. Without a solution to the growing population of expired satellites, old rockets and other debris, the safe use of SSOs will soon become impossible.

While SSO surveillance satellites have the advantage of photographing ground structures over and over with the same lighting conditions, and making the job of photo analysts relatively easy, SSO missions will have to be discontinued. Such orbits are actually dinosaurs in the age of virtual reality, data analytics, high-speed data transmission and other recently developed technologies.

With these new capabilities any comprehensive Earth-coverage network of redesigned ISR satellites can collect observational data, process this data and produce virtual results that represent critically important national security intelligence.

Such constellations can avoid most debris and adversarial threats, resulting in a highly resilient and hard-to-jam national security system. This is the kind of project also seems highly suitable for development by the new Space Development Agency (SDA).

Massive Martian ice discovery opens a window into red planet's history

Newly discovered layers of ice buried a mile beneath Mars' north pole are the remnants of ancient polar ice sheets and could be one of the largest water reservoirs on the planet, according to scientists at The University of Texas at Austin and the University of Arizona. The team made the discovery using measurements gathered by the Shallow Radar (SHARAD) on NASA's Mars Reconnaissance Orbiter (MRO). SHARAD emits radar waves that can penetrate up to a mile and a half beneath the surface of Mars. The findings, published May 22 in Geophysical Research Letters, are important because the layers of ice are a record of past climate on Mars in much the same way that tree rings are a record of past climate on Earth. Studying the geometry and composition of these layers could tell scientists whether climate conditions were previously favorable for life, researchers said. The team found layers of sand and ice that were as much as 90% water in some places. If melted, the newly discovered polar ice would be equivalent to a global layer of water around Mars at least 1.5 meters (5 feet) deep. "We didn't expect to find this much water ice here," said lead author Stefano Nerozzi, a graduate research assistant at the University of Texas Institute for Geophysics (UTIG) who is completing his Ph.D. at the Jackson School of Geosciences. "That likely makes it the third largest water reservoir on Mars after the polar ice caps." The findings were corroborated by an independent study using gravity data instead of radar, led by researchers at Johns Hopkins University. Nerozzi was a co-author. The papers have been published simultaneously in Geophysical Research Letters.

The authors think that the layers formed when ice accumulated at the poles during past ice ages on Mars. Each time the planet warmed, a remnant of the ice caps became covered by sand, which protected the ice from solar radiation and prevented it from dissipating into the atmosphere.

Scientists have long known about glacial events on Mars, which are driven by variations in the planet's orbit and tilt. Over periods of about 50,000 years, Mars leans toward the sun before gradually returning to an upright position, like a wobbling spinning top. When the planet spins upright, the equator faces the sun, allowing the polar ice caps to grow. As the planet tilts, the ice caps retreat, perhaps vanishing entirely.

Until now, scientists thought that the ancient ice caps were lost. The paper shows that in fact significant ice sheet remnants have survived under the planet's surface, trapped in alternating bands of ice and sand, like layers on a cake.

Co-author Jack Holt, a professor at the Lunar and Planetary Laboratory of the University of Arizona, said that the study provides new, important insights into the exchange of water ice between the poles and the midlatitudes, where his research group previously confirmed the presence of widespread glaciers, also using the SHARAD instrument.

"Surprisingly, the total volume of water locked up in these buried polar deposits is roughly the same as all the water ice known to exist in glaciers and buried ice layers at lower latitudes on Mars, and they are approximately the same age," he said.

Holt, who was a UTIG scientist and research professor for 19 years before joining the University of Arizona in 2018, has been a co-investigator with SHARAD since the spacecraft arrived at Mars in 2006.

Nerozzi said that studying this record of past polar glaciation could help determine whether Mars was ever habitable.

"Understanding how much water was available globally versus what's trapped in the poles is important if you're going to have liquid water on Mars," Nerozzi said. "You can have all the right conditions for life, but if most of the water is locked up at the poles, then it becomes difficult to have sufficient amounts of liquid water near the equator."

Chinese lunar rover's "lucky" find could unlock secrets of moon and earth

China's Yutu-2, the first rover on the far side of the moon, has found materials from deep inside the moon that could help unravel the mystery of the lunar mantle composition and the formation and evolution of the moon and the earth. Using data obtained by the visible and near infrared spectrometer installed on Yutu-2, a research team led by Li Chunlai, with the National Astronomical Observatories of China under the Chinese Academy of Sciences, found that the lunar soil in the landing area of the Chang'e-4 probe contains olivine and pyroxene which came from the lunar mantle deep inside the moon. The first important scientific discovery of the Chang'e-4 probe since it made the first-ever soft landing on the far side of the moon was published online in the latest issue of the academic journal Nature. The moon comprises a core, mantle and crust, like the earth. With the evolution of lunar magma, the light plagioclase rose to the upper layer to form the lunar crust, while the heavier olivine and pyroxene sank to form the lunar mantle, Li said. "But since the lunar crust is very thick, and there has been no volcanic activity and plate movement on the moon for billions of years, it's hard to find materials from the lunar mantle on the surface," Li said. The composition of the lunar mantle has long been the subject of theory. Neither the lunar samples from missions by the United States and Soviet Union, nor the remote sensing probes orbiting the moon have provided direct evidence of the accurate composition of the lunar mantle. Chinese scientists focused on a special area on the far side of the moon - the South Pole-Aitken (SPA) Basin, which was formed by a celestial collision over 4 billion years ago. With a diameter of 2,500 km and a depth of about 13 km, the basin is the oldest and largest impact crater on the moon.

After Chang'e-4 successfully landed on the Von Karman Crater in SPA Basin on Jan. 3 this year, the Yutu-2 rover obtained good quality spectral data at two sites.

"The data, unlike that obtained by Yutu on the near side of the moon, gave us a pleasant surprise," said Li.

Analysis showed the lunar soil in the landing area contains a large amount of olivine, low-calcium pyroxene and a small amount of high-calcium pyroxene, which are very likely from the lunar mantle, Li said.

So how did the materials from deep inside the moon get there?

After analyzing the high-resolution remote sensing images and the hyperspectral data, the researchers believed the materials were ejected from a 72-km-wide crater named Finsen to the northeast of the Von Karman Crater.

Li explained that after the SPA Basin was formed, more small asteroids crashed into the area, leading to more small craters. The collision that caused the Finsen Crater might have been so violent that the materials were knocked into the Von Karman Crater.

When scientists were selecting the landing site for Chang'e-4, flat areas were given priority. However, most of the flat areas on the moon are basalt formed as magma solidified.

It was lucky that Chang'e-4 probe landed in a region where the basalt is covered by lunar mantle debris.

"Furthermore, the rover is driving at the edge of the ejecta. According to our calculation, it might reach the basalt area in another 2 km or so. When it reaches the basalt area, we can compare the composition of the different lunar soils," Li said.

He said the study could provide a reference for a future mission to collect and return with samples and even the construction of a lunar base.

If the planned Chang'e-6 probe can go to that area, it would not only get the first-ever sample from the far side of the moon, but also have the chance to collect samples of materials coming from deep inside the moon, Li said.

"Most of the evolution of the moon happened about 3 billion years ago, while the early history of Earth before 3 billion years ago has been erased by geological activities. The moon is like a fossil that gives a glimpse of the early history of Earth," Li added.