India's reusable launch vehicle is operational

During this period, a two-stage-to-orbit (TSTO) reusable launch vehicle is developed by the Indian Space Research Organisation (ISRO). This follows successful testing of smaller, scaled-down versions, which demonstrated important technologies such as autonomous navigation, guidance and control, hypersonic and scramjet flight, a reusable thermal protection system, and re-entry mission management. An early prototype in 2016 achieved a speed of Mach 5 and maximum altitude of 40 miles (65 km)– not quite enough to reach outer space, which is generally considered to begin at a height of 62 miles (100 km).

 It lasted for 13 minutes and covered a distance of 280 miles (450 km), steering itself to an on-target splashdown to land (ditch) in the Bay of Bengal. Not designed to float, the vehicle disintegrated on impact and was not recovered. Known as the Hypersonic Flight Experiment (HEX) this was the first in a series of five tests. The four subsequent iterations were more advanced and enabled landing, return flights and scramjet propulsion experiments. These would eventually culminate in the finalised version, able to transport cargo into orbit, return safely to Earth and be re-used.

India had already launched astronauts into space by 2021, in a small capsule atop a GSLV rocket. The addition of a reusable launch system greatly expands ISRO's capabilities in space – enabling longer, more complex and commercially successful missions, while cutting launch costs by a factor of ten. This comes at a time when various new space planes are being developed by other countries and space agencies, making access to space increasingly affordable and routine.

Mars Science Laboratory is shutting down

This 900 kg (2,000 lb), six-wheeled rover has been transmitting back to Earth since 6th August 2012, the day it touched down on Mars.  Although its planned mission duration was around two years, it continued to be operational for considerably longer, like the previous rovers, Spirit and Opportunity. In fact, its onboard plutonium generators carried enough heat and electricity to last 14 years. By 2026 the machine is finally grinding to a halt. The last signal is received from the rover this year.

Various campaign groups voiced concerns, including Greenpeace, Friends of the Earth, the RSPB and WWF, as well as conservation organisation The National Trust, and developmental charities Oxfam and Christian Aid, alongside Hillingdon Council – a local government in West London. Among the biggest concerns were the impacts on local communities. Environmental campaigners warned that the increased CO2 caused by the additional flights would make it harder for the UK to meet its commitments to the Paris climate agreement.

Many people also resented London gaining yet another major project, drawing money away from the rest of the UK. The widening gap between London and everywhere else had already created a worrying socio-economic divide. This ever-growing sense of inequality may have been a contributory factor in the Brexit referendum result. The arguments from the opposition side were strong. In the end, however, the importance of Heathrow as an international transport hub and a catalyst for wealth generation in London and the South East was deemed too great. The construction of its third runway would be completed in 2026.

Youthful regeneration of aging heart muscle via GDF-11

In the previous decade, researchers identified an obscure blood protein called GDF-11. This was shown to have regenerative properties upon the cardiac muscle in age-related diastolic heart failure. The substance was found to be present at high levels in youth, and lower levels in old age. When elderly mice were supplemented with increased GDF-11, it had a dramatic effect on their hearts – restoring heart size and muscle wall thickness to a much earlier state.

Demonstrated that age-related cardiac hypertrophy can be reversed via exposure to a young circulatory environment. These experiments revealed that age-related cardiac hypertrophy is at least in part mediated by circulating factors, such as GDF11, which is able to reverse the condition. The reversal of cardiac hypertrophy in old mice exposed to a young circulation cannot be explained by a   reduction in blood pressurein the older mice. An extensive proteomics analysis was performed on the serum and plasma of the animals. GDF11 was reduced in the circulation of aged mice and its levels were restored to those in young animals by parabiosis.

This offered a potential way of treating heart failure and aging in people. A series of clinical trials, beginning in the late 2010s, confirmed this. By 2026, it's becoming fairly routine for doctors to repair cardiac damage and restore human hearts to earlier states, based on the GDF-11 protein. Along with stem cells and other advances this decade, science is gradually chipping away at the factors which cause people to die.